The present invention relates to a transportable apparatus for use in unloading material from a dump truck. More specifically, the present invention relates to a transportable apparatus that includes a hopper assembly that collects and guides material onto a conveyor assembly as the material is unloaded from a dump truck.
Vehicle-mounted, extendable concrete conveyor systems, such as shown in U.S. Pat. No. 4,624,357, have been in wide use for some time. Vehicle-mounted conveyor systems of this type have been found to be very useful because the concrete, or other aggregate material, can be transferred to a location at the work site that may be located a considerable distance from the supply of material. The vehicle-mounted conveyor system has proven to be very useful since the entire conveyor system can be quickly and easily moved by simply moving the vehicle on which the conveyor system is mounted. The conveyor system not only can be moved around the work site, but also includes a discharge conveyor assembly having a telescoping boom that can be extended and retracted, rotated about a vertical axis, and elevated to considerable heights. The vehicle-mounted conveyor system identified above can be moved from a working position to a transporting position and the entire vehicle and conveyor system can be transported over highways to travel between various work sites.
The extendable discharge conveyor assembly of the conveyor system includes a moving discharge conveyor belt that is fed by a second, infeed conveyor assembly. One end of the infeed conveyor assembly is positioned to receive a supply of concrete from a ready-mix truck or other type of delivery means. The infeed conveyor assembly transfers the material onto the discharge conveyor belt, which in turn transports the material to the desired point at the work site.
In currently available vehicle-mounted conveyor systems, the infeed conveyor assembly has a fixed length and is mounted to a main turret on the vehicle body. The infeed conveyor assembly is rotatable about the main turret such that the infeed conveyor assembly can be positioned at various locations around the vehicle. In addition, the entire infeed conveyor assembly is typically pivotally mounted to the main turret about a horizontal axis such that the outermost end of the infeed conveyor assembly can be raised and lowered as desired. For example, the entire infeed conveyor assembly can be raised above the vehicle and stored in a transporting position above the vehicle cab. Since the maximum length for the vehicle, including the discharge conveyor assembly and the infeed conveyor assembly in their transporting position, should not exceed 40 feet, the overall, fixed length of the infeed conveyor assembly is typically 40 feet.
The self-propelled, vehicle-mounted conveyor system is often used to transport aggregate materials, such as sand or loose gravel, supplied by a dump truck. Typical dump trucks have a bed that can be lifted upward relative to the vehicle to unload materials from within the bed. A rear tailgate extends across the width of the bed and often times includes a coal chute. The coal chute is substantially more narrow that the rear tailgate and includes a door that can be selectively opened or closed. As the bed of the dump truck is lifted, the material within the bed exits through the coal chute in a contained and controlled stream that can be fed directly onto the infeed conveyor assembly for the vehicle mounted conveyor system described above.
Although many dump trucks include a coal chute, a significant number of the dump trucks currently in use include only a tailgate that opens across the entire width of the dump truck. The width of a conventional dump truck is approximately 102 inches and a dump truck thus unloads material across its full width at a height not more than 30 inches above the ground. The above-described infeed conveyor assembly contained on the vehicle mounted conveyor system can not be used alone to unload this type of dump truck since the change in height of the infeed conveyor over the width of the dump truck exceeds the unloading height for the dump truck. For example, when the infeed conveyor assembly is on an incline of approximately 20.degree., the change in height of the infeed conveyor assembly is approximately 37 inches over the 102 inch width of the dump truck body. Therefore, if a dump truck backs up directly to the conventional fixed length infeed conveyor assembly, the height of the infeed conveyor assembly will exceed the unloading height for the dump truck along a portion of the width of the dump truck body.
To overcome the unloading problems identified above, the material contained within the bed of the dump truck is stockpiled and a skid-steer loader or other similar type of equipment is used to deposit the aggregate material into an independent hopper positioned above the infeed conveyor assembly. The hopper is required to accumulate the supply of aggregate material as the material is supplied by the skid-steer loader. As can be easily understood in the above description, the use of a skid-steer loader to supply the aggregate material that was previously stockpiled by unloading the entire bed of the dump truck introduces a separate operating step and requires additional personnel to supply the aggregate material to the infeed conveyor assembly of the vehicle mounted conveyor system.
Therefore, it is a primary object of the present invention to provide a transportable apparatus that can be used to directly unload the aggregate material from the bed of a dump truck onto a conveyor assembly, such as the infeed conveyor assembly of a vehicle mounted conveyor system. Further, it is an object of the present invention to provide a transportable apparatus that includes an inclined ramp having a pair of spaced support platforms that receive the wheels of a dump truck as the dump truck is driven onto the inclined ramp. Additionally, it is an object of the present invention to provide a hopper assembly mounted to the rear end of the inclined ramp to receive the aggregate material unloaded from the dump truck and direct the material onto the conveyor assembly. It is a further object of the present invention to provide a wheel assembly on the inclined ramp that is movable between a transport position and a loading position such that the inclined ramp is both stable during the unloading of a dump truck and can be transported by a conventional vehicle.
Additionally, it is an object of the present invention to provide a hopper assembly that includes a hopper bin extending along the entire width of the dump truck bed and having a significantly smaller discharge opening positionable above a conveyor assembly. Further, it is an object of the invention to provide a hopper bin that is movable to numerous positions between an upper, transport position and lower, unloading position.